The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in the present disclosure and are not admitted to be prior art by inclusion in this section.
More and more, users wish to accessorize their computing devices. A user may wish to play music on his or her tablet computer using peripheral speakers or video on an auxiliary display. Manufacturers of these computing devices often wish to maintain the highest-quality experience for those using their devices by offering tested and proven accessories. In contrast, third parties may instead wish to sell accessories that the manufacturer has not tested or proven.
In an attempt to ensure that only tested and proven accessories are used by their computing devices, many manufacturers require their computing devices to authenticate accessories before use. Accessories can be authenticated through secure communication between the computing device and the accessory, generally using a secret stored on the accessory.
This secret, however, can be discovered by third parties. In some cases, for example, accessories include a chip that stores the secret in read-only memory within the chip. The chip uses this secret to establish secure communications to authenticate the accessory. A third party, however, may reverse engineer the chip, layer-by-layer, and, using sophisticated image-processing techniques, discover the secret within the read-only memory on the chip. With the secret, the third party can duplicate the functionality of the chip with an inauthentic chip, also called a “clone.” This clone can then be used to fool the computing device into authorizing use of inauthentic accessories.